Breathe easy

Illnesses relating to breathing difficulties are on the increase. According to a recent report from the European Respiratory Society (ERS), conditions of the lung cause one in 10 deaths in Europe, with mortality as a result of lung cancer and chronic obstructive pulmonary disease (COPD) expected to rise in the future. In the UK, meanwhile, around one in 12 adults and one in 11 children are treated for asthma.

And because these cases are so common, they generate a huge health and societal cost. The ERS report estimates that individual cases of CPD cost €6,147 each year, while for asthma the cost is €7,443.

Counting the cost

One reason for these costs has been the development of a range of drugs to treat these conditions, which can vary from individual to individual. There are several different types of asthma – allergies, exercise-induced, cough-variant and occupational. The major cause of COPD is smoking, but it can also be caused by fumes, dust, air pollution and genetic disorders.

This variety of drugs presents challenges for their effective packing and dispensing. Pressurised Metered Dose Inhalers (PMDIs) have proved particularly effective because they are able to deliver a precise dose of medication - and by providing the energy for the drug delivery through the use of a propellant, the required particles are dispensed independently of the patient’s effort.

Of paramount importance in the development of any system is that it is robust and reliable to ensure that the drug is adequately protected and that the inhalation system continues to function properly. And since many of the users of these systems will be incapacitated in some way, ease of operation is also vital. Our Twist’n’hale design, for example, features a turning wheel on the side of the container. When the cap is opened, the wheel is rotated clockwise in a single movement up to the stop point, which releases the dose.

The properties of the drugs need to be taken into consideration as does the method of dispense. There are many different types of powder blends, and the flow rate and fine particle fraction will vary from drug to drug. New powdered formulations for nasal inhalation have also opened up challenges.

Appearance important

The appearance of inhalation systems is also important. Patients need reassurance that the drugs they are taking are reliable and of good quality, so how they are packaged can play a significant part in patient confidence. Attention therefore also needs to be paid to the decoration of the inhalers.

It is important that inhaler manufacturers work closely with their customers to understand the particular characteristics of each drug and how it needs to be handled and dispensed. Ease of filling on packing lines is another critical consideration.

Inhalation systems are complex structures with a number of separately manufactured parts – including the outer body, the dispensing mechanism, actuator and mouthpiece – which then have to be carefully assembled to create the finished inhaler. Packaging suppliers continue to invest in the latest advanced moulding and automated assembly equipment, ensuring each piece is manufactured to precise tolerances and accurate dimensions.

As well as understanding the characteristics of the drug, the other main factor in the initial design of the inhaler is whether it is to be a single-use or re-usable version. For re-usable systems, ease of removal and replacement of the powder is critical. One noticeable recent trend has been the growth in popularity of capsules over the more common blister formats. As drug manufacturers continue to work towards the next breakthrough treatments for COPD and asthma, these will no doubt provide fresh challenges to inhalation system designers and manufacturers.